Atmospheric currents allow birds to fly more efficiently than swimming

An international study published in the journal Science, involving the Spanish Research Council (CSIC), has found that certain birds can fly using atmospheric currents with lower energy costs than swimming. This discovery challenges the long-held scientific paradigm that identified swimming as the most efficient form of locomotion among vertebrates.

Researchers monitored 850 individuals from 38 species of birds and bats across various global regions over a 17-year period. By combining over 1.4 million GPS locations with detailed data on winds and thermal updrafts, the team analyzed the atmosphere as a direct energy source for flying species.

The study identified two primary movement strategies: continuous flapping and atmospheric soaring. Soaring species, such as the Andean condor and vultures, can travel long distances while flapping their wings for only 0.1% to 7% of their total flight time. These soaring birds recorded energy costs up to 79% lower than similar-sized species that rely exclusively on constant flapping.